Marshall Origin SOS

whoanelly15

Tele-Afflicted
Joined
Aug 30, 2017
Posts
1,247
Location
USA
I have a 20-watt combo Marshall Origin. Little over a year old. Have not had any issues with it. Only play at home and only a couple times per week with this particular amp. Generally, for 20-30 minutes at a time at mid-power and with volume 1-2. Has not left my basement since I got it new.

Several days ago, I put in a new speaker (matched to 16-ohm output). Sounded great. Played it a couple times in short intervals, mostly clean. Last night, I was playing for about 15 minutes when I heard a pop and lost some volume. Still had a good sound, but noticably quieter. Turned up a little and heard what sounded like some speaker breakup/crackle with chording. Shut it off.

Worried it was the new speaker, I plugged my 2x12 cab into it, also 16-ohm, then turned it on - same thing. Turned it off again. Plugged the combo speaker back in. Turned it on and it seemed to work fine.

Maybe a stock tube starting to go? Would appreciate any advice or recommendations you folks might have. I have the number for a good amp tech in the area, but if just a tube swap would be a more cost effective way of problem-solving, I can handle that. Thanks in advance.
 
Last edited:

fender4life

Friend of Leo's
Joined
Sep 18, 2011
Posts
4,667
Location
los angeles
More than likely, yes....tube. First thing i'd do is turn it on and watch the power tubes for a few minutes and see if one starts glowing VERY bright orange. Turn it off as soon as you see that because it;s what is called red plating and it can damage the amp. Replace the power tubes immediately. If it's a preamp tube the best way to do that is swap a new tube into one position and try it. If no joy, replace the original tube and try the new one in the next position and do that with all preamp tubes. If no joy then it could be a number of internal issues but my advice to anyone with a tube amp is ALWAYS have a set of all tubes in the amp on hand because tubes these days are not reliable at all and tubes are also the most common failure and can be determined by swapping.
 

whoanelly15

Tele-Afflicted
Joined
Aug 30, 2017
Posts
1,247
Location
USA
More than likely, yes....tube. First thing i'd do is turn it on and watch the power tubes for a few minutes and see if one starts glowing VERY bright orange. Turn it off as soon as you see that because it;s what is called red plating and it can damage the amp. Replace the power tubes immediately. If it's a preamp tube the best way to do that is swap a new tube into one position and try it. If no joy, replace the original tube and try the new one in the next position and do that with all preamp tubes. If no joy then it could be a number of internal issues but my advice to anyone with a tube amp is ALWAYS have a set of all tubes in the amp on hand because tubes these days are not reliable at all and tubes are also the most common failure and can be determined by swapping.
Thank you. Any recommendations on where to buy? I have seen re-tube kits for the Origins listed on Reverb, but they're not cheap. And forgive my ignorance, but I would need a matched set of EL34's for the power section, correct? Or is it safe to replace just one?

A step further, if my goal was to get as much compression/gain out of this amp as the circuit can allow, what tubes would you all recommend? Or would this be more of a preamp tube characteristic? I have seen some helpful discussion on this in other discussions on TDPRI, but would appreciate some weighing in here.
 

Cyberi4n

Tele-Afflicted
Joined
Oct 28, 2020
Posts
1,241
Age
49
Location
Chester, Uk
EL34 Marshall-branded matched pairs are available on eBay here (U.K.) for £50. So you shouldnt need to be shelling out lots. The 20 is fixed bias isn’t it? You ‘should’ be safe to replace just one, with the caveat that you’ll likely be needing another one in a few months. If it was me I’d replace them both with a matched pair personally.

If you want to retube the whole amp though…..
 

Jakedog

Telefied
Ad Free Member
Joined
Mar 26, 2003
Posts
23,514
Location
The North Coast
Tubes in these are a PITA because you have to pull the chassis to replace them. That said, it’s not super hard or anything, just an annoyance.

Do the EL34s as a pair. My feeling is that it’s probably a tube issue. I don’t want to rain on your parade, but if it’s not a tube issue, but instead something else frying a tube, you’ll know soon enough.
 

fender4life

Friend of Leo's
Joined
Sep 18, 2011
Posts
4,667
Location
los angeles
I'd buy a set regardless of whether it's a tube issue or not because like i said above you should absolutly always have a spare set both in case you eed it at a gig and just as importantly to use to see if tubes ARE the issue. As for what type, thats a matter of taste but the facr you aren't sure what to get tells me you probably won't notice anything or at least much. I'm not a big fan of JJs but they are ok. I've been using modelers for a long while now so not sure what the vurrent state os as tubes go, whats good, whats reliable etc. But JJs are fine if not the most incredible sounding tubes. Probably whats in the amp stock anyways tho they usually have the marshall brand on them but are likely rebranded JJs. Marshall always puts thier log on them. Also, i believe the origin 20 is cathode biased so you are lucky in that 1-you don't have to worry about getting the amp biased and 2-mathing is not a big deal. But get a matched set anyways since that is the way they come anyways unless you buy a single. But buy a pair.
 

whoanelly15

Tele-Afflicted
Joined
Aug 30, 2017
Posts
1,247
Location
USA
The high cost is mostly due to the masking/electrical tape on the back :)

View attachment 939166

I don’t know about “unknown”, but I do have a couple of “off the beaten path” guitars I enjoy.

One is my Ibanez Jet King 2 (Google pic)

View attachment 987141

It obviously looks cool. It balances nicely, sort of like a Jazzmaster or Jaguar. Tonally it’s a nice complement to my Les Paul. Similar enough to substitute, different enough to stand in its own.

I’ve modded mine so that the rocker switches do series/parallel rather than full/split. I’d like to incorporate a bass cut control into this one as well.

I’m on the lookout for a JTK30H, which is the semi-hollow version with (not quite but sort of) P90 pickups.

The other is my Reverend Tricky Gomez.

View attachment 987143

The influences are clear. The pickups are aesthetically Filter’Tron, but apparently more mini-humbucker in construction and sound. This guitar threatens to become my favorite whenever I play it for a while. Lots of great tones from mean to sweet, the larger (but not very deep) body is a nice change, and you can’t look bad with this hanging off your shoulder.

Mine currently has some slight visual differences; chicken head knobs and a poker chip under the switch. It’s currently awaiting a Tru-Arc bridge, and I’ve been contemplating a Varitone.

Tubes in these are a PITA because you have to pull the chassis to replace them. That said, it’s not super hard or anything, just an annoyance.

Do the EL34s as a pair. My feeling is that it’s probably a tube issue. I don’t want to rain on your parade, but if it’s not a tube issue, but instead something else frying a tube, you’ll know soon enough.

I'd buy a set regardless of whether it's a tube issue or not because like i said above you should absolutly always have a spare set both in case you eed it at a gig and just as importantly to use to see if tubes ARE the issue. As for what type, thats a matter of taste but the facr you aren't sure what to get tells me you probably won't notice anything or at least much. I'm not a big fan of JJs but they are ok. I've been using modelers for a long while now so not sure what the vurrent state os as tubes go, whats good, whats reliable etc. But JJs are fine if not the most incredible sounding tubes. Probably whats in the amp stock anyways tho they usually have the marshall brand on them but are likely rebranded JJs. Marshall always puts thier log on them. Also, i believe the origin 20 is cathode biased so you are lucky in that 1-you don't have to worry about getting the amp biased and 2-mathing is not a big deal. But get a matched set anyways since that is the way they come anyways unless you buy a single. But buy a pair.
I had another tube amp a few years back with JJ’s, and they were fine, but that was a very different circuit. From what I have read, the stock Origin tubes are rebranded, MIC JJ’s. Those are not hard to be found and would be among the cheaper options for trying to diagnose by trial.

On another thread here, the Tung-Sols were recommended to access a little more gain and are generally well-regarded. Mullard’s are also gettable. There is also a used but affordable set of RFT’s on Reverb currently.
 

fender4life

Friend of Leo's
Joined
Sep 18, 2011
Posts
4,667
Location
los angeles
I had another tube amp a few years back with JJ’s, and they were fine, but that was a very different circuit. From what I have read, the stock Origin tubes are rebranded, MIC JJ’s. Those are not hard to be found and would be among the cheaper options for trying to diagnose by trial.

On another thread here, the Tung-Sols were recommended to access a little more gain and are generally well-regarded. Mullard’s are also gettable. There is also a used but affordable set of RFT’s on Reverb currently.
I've used the tung sols both 34's and 12AX7's. The 34's.....meh....they're mediocre to my ear. The 12AX7's on the other hand IMO sound great and bright. Problem with those from day one was noise that was a problem with the majority of them. I bought a bunch and i found about one in 4 or 5 didn't hum loudly like the rest did. If you can afford to buy a bunch and pick the good ones out they are IMO great tubes. Maybe my fav premp tube. I don't know if they rectified the issue but i doubt it because i used them for a number of years since they debuted in i guess around 2010 roughly and they never fixed that issue. I think it;s just the design that makes it impossible to make them consistently good. But the power tubes...tried the 34s and 6L6 and both were to my ear rather mediocre. Supposedly sturdy tho from what i recall reading if memory serves.
 

Jakedog

Telefied
Ad Free Member
Joined
Mar 26, 2003
Posts
23,514
Location
The North Coast
I had another tube amp a few years back with JJ’s, and they were fine, but that was a very different circuit. From what I have read, the stock Origin tubes are rebranded, MIC JJ’s. Those are not hard to be found and would be among the cheaper options for trying to diagnose by trial.

On another thread here, the Tung-Sols were recommended to access a little more gain and are generally well-regarded. Mullard’s are also gettable. There is also a used but affordable set of RFT’s on Reverb currently.
I know GT re-labels their tubes, so I have no idea what the ones I use actually are. But they labeled as the GT E34LS. I get the #7 sets for my EL34 amps. They’re not more breakup, but the opposite. I use them because they’re advertised to *up* both power and clean headroom.

I’ve been using them in Marshalls for probably 15 or so years now. I put a set in my origin 20 combo when I bought it. I beat the snot out of it for a year and a half, then sold it to my band mate. He’s been beating on it for a year now. Those tubes are great. They last, and they punch. Not the ticket if you’re going for more power amp breakup, however.
 

whoanelly15

Tele-Afflicted
Joined
Aug 30, 2017
Posts
1,247
Location
USA
From what I know of the scheme for the O20, V1 is glowing a little brighter than V2, and V3 brighter than the other power tubes. But, V3 is for the effects loop, and I’m not even running anything through that. Didn’t seem to change after running for 5-6 minutes on low power. While I let it sit, I double checked that all cables were good. Then let it sit for another 5 minutes at mid power (for the record, though I’m no expert, I don’t think the power scaling system on these would actually make a difference here, but still felt like the right step to take). Then, I turned it off and plugged the speaker back in. I did hear a little extraneous noise/crackle that I don’t normally hear within 2-3 seconds of powering it on a second time, but didn’t lose any volume this time. And that was through my pedalboard, so could have been a patch cable or my always on tuner, which is very noisy with any movement at all - should’ve gone straight in. Amp seemed to work great after that with about 45 minutes of playing. I powered down. Waited a couple minutes. Powered back up again and it seemed fine. Worked as well as ever.

I’m glad that it behaved tonight, but I’m not one to ignore a potential warning sign with something like this. It’s the nicest amp I’ve ever owned. I did go ahead and order some used tubes. If it happens again, I’ll try a swap. If not, I’ll keep ‘em in the drawer until the next time.
6FC93604-FBCB-4A1E-A795-4360CFCB9691.jpeg
BE7B073B-8389-40DD-9F60-11FDADEDC02B.jpeg
11484DD5-BCDB-4C24-8659-9272482587A2.jpeg


For those who were wondering, you can clearly see the JJ’s logo on these stock, Marshall-branded tubes.
 

Dacious

Doctor of Teleocity
Joined
Mar 16, 2003
Posts
10,801
Location
Godzone
Have you tried all three power positions? If so - try the following.

There's a cathode follower in the effects loop that's active whether the loop is switched on or not. It's V2. If you've got a spare 12AX7 I'd swap it into the middle position.

You could even temporarily swap V1 and V2. If the Tilt works on one side or the other more it suggests it's that tube. The stock tubes are Shuguangs - only one of them or a JJ should be used in V2
 

whoanelly15

Tele-Afflicted
Joined
Aug 30, 2017
Posts
1,247
Location
USA
And just like that, it’s a real problem now. Played great the last couple days, then this morning while playing at just a basement volume, a very loud noise, a lot like a wild distortion pedal but without any notes ringing through, came blaring out. Tried to turn gain and master volume all the way down quickly, which did nothing, the. Powered it off. Waited a bit. Powering back up produced no sound at all. There is power, but no sound. New tubes probably won’t be here until later this week. Thumb-twiddling until then. Bummer.
 

KirkDahnke

TDPRI Member
Joined
Mar 13, 2022
Posts
24
Age
52
Location
Kansas City
The white branded Marshall tubes are just MIC stuff. Its the red ones that are JJs. I think the preamp tubes are the white ones. At least on my 20H they were.
 

whoanelly15

Tele-Afflicted
Joined
Aug 30, 2017
Posts
1,247
Location
USA
Bad preamp tube. Once I actually checked, one was badly microphonic. Got a replacement EH tube for $15 from the local tech. Back in business. All is well in the world.
 




Top